Up, up and away
Scientific balloon flights make history
In a history-making venture, NASA educators and high school and college students launched instrumented balloons into the stratosphere and then recovered the payloads at sea after they beamed back stunningly beautiful photographs of the coastline of Massachusetts’ North Shore.
The successful flight of one large balloon, called a “BalloonSat,” capable of lofting heavier loads into “near space”—where the atmospheric pressure is a sparse fraction of what it is on the ground; the daytime sky appears black; and the curvature of the Earth can be imaged by onboard cameras—was the first-ever sea recovery of a “BalloonSat” launched from the continental United States, according to NASA educator William Waller, associate professor of physics and astronomy at Tufts. The flight in July also achieved the farthest distance of recovery—13 miles northeast of Halibut Point—he said.
“To make it work, we needed help from NASA ballooning experts, who traveled to Rockport, Mass., from Puerto Rico, New York and Vermont,” Waller said. “We also received vital support from several local ham operators and boaters.”
The Northeast Ballooning Workshop—the first of its kind in New England—was co-hosted by the Massachusetts Space Grant Consortium and the New England Space Science Initiative in Education, regional agents of NASA’s far-flung education program.
Participants included students from Kuss Middle School in Fall River, Mass., one of the nation’s 164 NASA Explorer Schools, a program that brings engaging mathematics, science and technology learning to educators, students and families. The Fall River students were already licensed ham radio operators who tracked the balloons in flight.
Also participating were students from Tufts, MIT, Boston Latin High School and Rockport High School. All of the students played critical roles, Waller said, including soldering the electronic circuitry, assembling the payload modules, calibrating the instrumental responses, launching the balloons, tracking the radio signals and retrieving the payloads at sea.
The first balloon launched carried a “CricketSat” payload, consisting of a matchbox-size temperature sensor, circuit board and battery that communicated a beeping signal over a ham radio frequency. The time between beeps is sensitive to temperature, which changes drastically with altitude, Waller said. By calibrating the instrument’s response to a cup of ice, the hot interior of a car and other environments of known temperature, the students were able to interpret the balloon’s signals once it was aloft.
With help from the Puerto Rican ham radio operators, the CricketSat payload was tracked to a maximum height of 32,000 feet, a temperature of minus 40 degrees Fahrenheit and a distance or more than 130 miles—more distant than any prior CricketSat tracking, Waller said.
The construction and calibration of the heavier BalloonSat model took up most of the three-day workshop in July. Oscar Resto and Gladys Muńoz of the Puerto Rico Space Grant Consortium guided the students through the many steps of crafting the circuitry and building the payloads. The students made three BalloonSat modules, two of which were launched.
To ensure that the payloads could be retrieved at a reasonable distance from shore, the flight had to be terminated well before the balloon reached its maximum attainable altitude of 90,000 feet.
“The stunning pictures of Cape Ann from an estimated altitude of 16,000 feet are positive proof that scientific ballooning can be successfully pursued by motivated teams of students and educators,” Waller said. “Perhaps more important was the teamwork and self-esteem that arose from our venture into the stratosphere,” he added.
Waller said he hopes to continue with student-focused scientific ballooning projects in New England.